People magazine reports Britney Spears canceled a session at Millennium Dance Complex after seeing a hoard of photographers outside the West Hollywood facility waiting to quiz her about 16-year-old sister Jamie Lynn’s pregnancy. “She wanted to try out a new dance routine,” a source told the mag, but after spotting all the commotion, the 26-year old “freaked out and just kept driving.” Why so press shy all of the sudden? “Britney said that she doesn’t want to deal with the media because she is still shocked [about Jamie Lynn’s pregnancy news],” the source added. “She feels that she needs peace and quiet.”